Heretofore, it has been well known to have orthodontic wires for delivering force components to teeth made of 18-8 stainless steel wire. Such wire has a modulus of elasticity of around 30.times.10.sup.6 psi. It has also been known to provide orthodontic wire of a cobalt chromium alloy which likewise has a modulus of elasticity at least as high and sometimes higher than stainless steel wire.
With the advent of lighter force requirements being the trend in orthodontic treatment, various nickel titanium wires have been developed and defined as having a beta titanium alloy such as disclosed in U.S. Pat. No. 4,197,643. These beta titanium wires have a much lower elastic modulus of about 10.times.10.sup.6 psi. Accordingly, such wires deliver a substantially lower force to the teeth when used in conjunction with orthodontic appliances.
There have also been developed orthodontic wires considered to be super elastic and of a nickel titanium alloy and having even a substantially lower elastic modulus than beta titanium wire. An example of a superelastic wire is disclosed in U.S. Pat. No. 5,044,947. For example, such wires have a modulus of elasticity of around 4 to 5.times.10.sup.6 psi. These wires may also be temperature sensitive for returning to a desired shape when placed in the mouth.
It is desirable where lower force mechanics are used for orthodontic treatment to utilize a wire having a lower modulus of elasticity to provide a constant moderately low level force than that obtainable with stainless steel wires. Thus, the beta titanium wires have been generally utilized where a lower force is desired. One disadvantage of such wire is that it is relatively high in cost compared to the stainless steel wires. Moreover, the formability of a beta titanium wire is still not as good as wires having higher force components, while it is better than nickel titanium wires.